Electrical attachment-plug



W. C. TREGONING.

ELECTRICAL ATTACHMENT PLUG. APPLICATION FILED FEB.6,1913- RENEWED FEB. 10,1919.

Patented Jan. 20, 1920.

luvs/iron UNITED STATES PATENT. OFFICE.

CORPORATON OF ILLINOIS.

' WILLIAM C. TREGONING, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO BENJAMIN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A

ELECTRICAL ATTACHMENT-PLUG.

Application filed February 6, 1913, Serial No. 746,481.

wherein a relatively small number of parts are particularly related to permit the screw member thereof to be rotated without twisting the electrical cable connection. A further object of the invention is to provide a plug of this character wherein the terminal supporting member and the said screw memher are separably united by a split ring providing a rotatable bearing between the parts. Another object of the invention is to provide a device of this character wherein the cable connecting member is particularly constructed to relieve the wire terminal connection of all strains. Further objects and advantages of the invention will be obvious from the detailed description given below, in connection withthe accompanying drawings illustrating various modifications of the invention.

In the accompanyingdrawings, Figule 1 is a side view of my improved attachment plug shown full size and as assembled for use. Fig. 2 is a perspective view of the two main plug parts in such separable relations as'occur in making terminal connections, and Fig. 3 is a perspective view of the split locking ring. Fig. 4 is a sectional view centrally of a complete plug considerably enlarged. Figs. 5 and (3 are perspective and sectional views respectively of two modified forms of the inner terminal-support and cable-connecting member of my invention.

Detailing my invention, the same comprises a hand-hold member 2 made of insulating material, such as a rubber composition or porcelain, and this member is of cylindrical form and has a roughened and milled outer surface to provide a good finger grip to rotate the same. provided with a reduced extremity 3 upon which a screw-shell 4 is securely fastened to Specification of Letters Patent.

Member 2 is also.

Patented Jan. 20, 1920. Renewed February 10, 1919. Serial No. 276,244.

permit screw-attachment with electric lamp sockets 'in general use, and is also constructed with a differential bore 5 and a rOHnded seat or channel 6 in its upper end surrounding said bore wherein a split ring 7 of spring metal may be removably confined and have a rotatable bearing, especially when said ring is engaged in locked relation with the butt basic portion of the plug, such butt basic portion consisting of a tubular member or thimble 8 forming a rigid part of the inner plug member which guides and supports the wire-connecting terminals. Thus, thimble 8 is a cylindrical piece made of insulating material, either rubber, composition or porcelain, and having an annular groove 9 to hold the bearing and locking ring 7. In Figs. 1 to 3 this piece 8 is shown as reduced in diameter at its lower or inner end to permit a sleeved and shouldered connection to be made with the band part 10 of the two-legged yoke 12 which also comprises a larger bottom rim 14 of circular form and of a diameter to bear constantly against the inturned end' 15 of the screw-shell 4 when the plug parts are completely assembled and therethrough provide a path for the electric current from the screw-shell to the spreading legs of the yoke forming an integral or fixed part of the rim.

An car 16 on one of the legs of the yoke carries a terminal screw 17 wherewith connect1on may be made with one wire 18 of the electrical cable or cord 20 when entered and extended through thimble '8. Said cable is not only guided by the thimble, but is also preferably secured within the thimble to relieve and prevent end pull or strain upon the terminal connections and for this purpose I provide said thimble with internal threads 21 which start at the bottom of the smooth bore 22 in the top of said thimble and whereby the said thi'mble may be first sleeved and then screw-threaded u on the end of said cable,the insulatin iiody and the woven covering of the cabfis being of a yielding character to permit such screw-threading operations without forming a screw-thread as a preliminary step in the cable itself.

To complete the electrical connection,lit is of course necessary to provide means to connect the other wire 19 of the cable with another contacting terminal for the plug and which, in the present instance, comprises the central metal cap 23 forming a '27 for wire 19.

center contact secured to the outer end of the tip basic portion or insulatin head 24: by a screw 25 which passes central y through said head and screw-engages the angular metal bracket 26 having the terminal screw The reduced extremity 3 of the hand-hold member 2 forms an insulating shield or sleeve which prevents shortcircuiting between the screw-shell 4 and the terminal-screw 27 or wire 19. Head 24 is slightl recessed to seat the base of bracket 26 an is made of suitable insulating m a terialto electrically insulate the brac et 26 from the rim l4 ofthe metal yoke which is shown as having its edge spun over the edge of the head. The bracket 26. is also preferably disposed with its upstanding portion at a point centrally between the two legs of the yoke so that ample room is given to connect and disconnect thewires at the binding screws and of course also to prevent short-circuiting between the parts. When all the parts are assembled, the spring ring 7 locks them together with a slight friction between the screw-shell and the yoke rim 14, thus giving a good electrical contact. However, the parts have perfect freedom of rotation so that hand-hold member2 and the screw-shell may be jointly rotated without twisting the cable 20 when a socket attachment is made. In separating the hand-hole member from the terminal supporting body, one end of the split ring is member for the wire lifted or sprung outward and the ring eX- panded and removed, which unlocks the parts, so that they'may be taken. apart as in Fig. 2 to permit of the attachment of the conducting wires to the binding-posts for the purpose of wiring the plug or to permit of the re-attachment of either one or both of such connecting wires inthe event they become detached from the binding-posts. The device is readily assembled by slipping the threaded shell back into position and replacing the locking spring.

In Fig. 5 a single uniting leg 28 is shown which in a sense is the equivalent of the bracket 26, in that it becomes the terminal that places the cap 23 and the fastening screw circuit. As modified, the bracket is extended to unite with the thimble 8, apractical union being effected by molding said bracket within the thereof. Then in lieu of a contact rim 14 with legs I use a metal contact rim or band 14 with a short leg or car 16 bent upwardly therefrom to hold a terminal binding screw for attaching the other wire that places the screw-shell in the electric circuit.

In Fig. 6 the device is modified to permit the terminal connection's 29 and 30 to be molded within or upon the insulating thimble 8 and head 24', thereby uniting all said parts together. The part 29 extends 25 in the electric thimble in the making 1 through the head 24 and is bent over at its outer end to provide a central contact for the plug in' lieu of the separate cap 23 shown in the other figures.

' While I have described the embodiments of the invention illustrated in the drawings in considerable. detail, it is to be understood that I do not desire to be limited thereto except as specified in the appended cla1ms,

independently-rotatable elements, carrying separate electrical contacts, one of said elements comprising an insulating thimble having a central bore with a smooth surface at its end, and a screw-thread intermediate its ends, a detachable terminal connection mounted on said thimble, and a mov; able bearing and locking rin rotatably and detachably uniting the said e ements.

3. In an electrical attachment plug, a separate thimble and head having an intermediate uniting metal part therefor, and one of said parts having an electric-current 'contact piece mounted thereon, in combination with a hand-hold member having a screwshell engaged with said contact piece, and a split ring to rotatably and detachably unite said thimble and hand-hold member together.

4. In an electrical attachment plug, a screw-shell and rotatable support, therefor, contact terminals and an insulating support therefor comprising a separate head and thimble, means to rotatably unite said shell support and said terminal supports, said thimble having a bore with internalscrewthreads adapted to screw-engagewith a cable connection when inserted therein to make wire connections with said terminals.

5. An attachment plug comprising an insulating member, a center contact supported thereon, cord gripping means, a metallic member connecting said insulating member and cord gripping means, and a binding screw threaded into said metallic member.

6. An attachment plug comprising an insulating member, a center contact supported thereon, cord gripping means, a metallic member connecting said insulating member and cord gripping means, screw threaded into said metallic member, said metallic member being electrically connected to said center contact.

and a binding tact supported by said insulating 7. An attachment plug comprising an insulating member having a substantially cy' lindrical opening therein, a substantially cylindrical cord gripping member rotatably mounted in said openin and a shell conmember.

8. An attachment plug comprislng an insulatingbutt basic portion, an insulating tip basic portion, a conducting member connecting the butt basic portion and the tip basic portions and preventing movement of either portion with respect to the other when the parts are assembled, a center contact for the tip basic portion electrically connected to the conducting member, a screw shell rotatable with respect to the basic portions, a second conducting member attached to one of the basic portions and electrically connected to the screw shell, and a bindingpost carried by each conducting member.

9. An attachment plug comprising an insulating butt basic member, an insulating.

tip basic member, a center contact supported I by said tip basic member, a metallic member mechanically connecting said basic members and electrically connected with said,

center contact, a binding screw threaded into said metallic member, and a screw shell contact swivel'ly mounted with respect to said tubular member and base.

10. An attachment plug comprising a butt basic portion, a tip basic portion having a center contact, a conducting member secured to the tip basic portion and permanently fixed to the butt basic portion, a

second conducting member mounted on one of the basic portions, a screw shell freely rotatable with respect to the basic portions and having a handhold, a binding-post carried by each conducting member, one of the conducting members being electrically connected to the screw shell while the other is electrically connected to the center contact,

. and supporting means for maintaining the screw shell in assembled relation to the basic portions without interfering with its rotation.

' 11. An attachment plug comprising an insulating tubular cord guiding member, an insulating head, a center contact supported by said head, a metallic member secured'to said tubular member, and a screw extending through said head and threaded into said metallic member and electrically connected to said center-contact, said metallic member having a screw threaded opening to receive a binding screw, and a screw shell contact swivelly mounted with respect to said tubular member and head. 12. An attachment plug comprising a butt basic portion, a tip basic portion, a conduct trically connected to the conducting member, a screw shell rotatable with respect to the basic portions, a second conducting member fixed to one of the basic portions and electrically connected to the screw shell, a binding-post threaded into each conducting member, and supporting means for mainsecond conducting member on one of the 7 basic portions, 2. center contact for the tip basic portion, a s'crew'rod passing through the tip basic portion and engaging one of the conducting members to electrically connect said center contact with'said conducting member, and a screw she'll electrically connected with the other conducting member and rotatable with respect to the basic portions. U

14. An attachment plugcomprising an insulating butt basic portion and a tip basic portion, the latter having a center contact, a conducting member attached at one end to the butt basic portion and at the other end to the tip basic portion, a second conducting member carried by one of the basic portions, a threaded shell rotatable with respect to the basic portions and having a handhold, one of said conducting members being electrically connected to the center contact and the other electrically connected to the threaded shell, and a binding-post directly carried by each conducting member, both said binding-posts being located within the threaded portion of the screw shell.

15. An attachment plug comprising an insulating butt basic portion, an insulating tip basic portion, a conducting member connecting the two basic portions to secure the same against movement independently of 7 each other when the parts are in assembled relation, a second conducting member associated with one of the basic portions, a screw shell contact rotatable with respect to the 'ing-post threaded when the basic portions are in assembled relation, a second conducting member mounted on one of the basic portions, one of the conducting members being electrically connected to the center contact andthe other having a lip which is in electrical engagement with the screw shell, and binding-posts on the conducting members.

17. An attachment plug comprising a butt basic portion, a tip basic portion, a conducting member having-one end secured to the butt basic portion and the other end connected to the tip basic portion, a center contact, for the tip basic portion electrically connected to the conducting member, a screw shell contact rotatable with respect to the basic port-ions, a second afiixed to one of the basic portions and electrically connected to the screw shell, a bindinto each conducting member, an insulating shield between the binding-posts for the center contact and the screw shell contact, and'provision for maintaining the screw shell in assembled relation to the basic portions without interfering with the rotation.

18. An attachment plug comprising a butt basic portion, a tip basic portion, a conducting member having one end secured to the butt basic portion and the other end connected to the tip basic portion, a second conducting member carried by one of the basic portions, a center contact for said' tip basic portion, a screw shell contact rotatable with respe'cttothe basic portions, said contacts being electrically connected respectively with the conducting members, a bindingconducting member the butt basic portion and the other end connected to the tip basic portion, a center contact for the tip basic portion, a screw shell contact rotatable with respect to the basic portions and having a hand-hold, two binding-screws located between said basic portions, one of said binding-screws being threaded into said conducting member, one of said binding-screws being electrically connected to the center contact and the other to the screw shell contact, an insulating lining for the screw shell integral with the hand-hold on the threaded shell and constituting a shield between the binding-screw for the center contact and the screw shell contact, and means for maintaining the screw shell in assembled relation with respect to the basic portions without interfering with its rotation.

In testimony whereof I aflix my signature in presence of two witnesses.

\VILLIAM C. TREGONING.

\Vitnesses:

R. B. MOSER, F. C. MUSSUN. 

